fix(webhooks): set content-type in webhook requests

[steebchen]

Description

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)

What's Changed

[vercel[bot]]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
hatchet-docs	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Jun 26, 2024 10:04pm